1. Field of the Invention
The present invention relates generally to an air bag unit for use in a motor vehicle and more particularly to a cover for such air bag unit.
2. Description of the Related Art
Japanese patent laid open No. 55/110643 discloses an air bag unit which includes a casing fixedly mounted in a steering wheel assembly, a gas generator arranged in the casing, an air bag communicating with the gas generator, and a cover adapted to cover the casing. The air bag is normally in a folded condition and is inflatable when gas under high pressure is fed from the gas generator upon the occurrence of an accident. The cover has a body and a top portion connected to the body via connecting and weakened portions formed therein. Upon the inflation of the air bag, the weakened portions are broken. Consequently, the top portion of the cover is divided into two separate pieces, which are open toward the driver of the vehicle. A reinforcing member is embedded in the cover to prevent separation of the two cover pieces from the body of the cover.
In such conventional air bag unit, the body of the cover must be rigid and thick to prevent separation of the body of the cover from the casing or the steering wheel assembly. However, this results in an increase in cost and weight of the entire air bag unit and also, prevents a compact arrangement of the air bag unit.